A substrate processing apparatus that performs a plasma processing on a semiconductor wafer (hereinafter, briefly referred to as a ‘wafer’) as a substrate includes a chamber capable of receiving the wafer and reducing an internal pressure, a mount (hereinafter, referred to as a ‘susceptor’) disposed at a bottom side in the chamber, and a shower head disposed to oppose the susceptor in the chamber. The susceptor serves as an electrode that is connected to a high frequency power supply and applies a high frequency power into the chamber while disposing the wafer. The shower head, which is grounded to serve as a ground electrode, introduces processing gas into the chamber. The substrate processing apparatus excites the processing gas supplied into the chamber by the high frequency power to generate plasma and performs the plasma processing on the wafer using the plasma.
However, in order to appropriately distribute the plasma in the chamber, in particular, in a space between the shower head and the susceptor, the substrate processing apparatus has been developed capable of controlling the distance of the processing space (hereinafter, referred to as a ‘gap’) between the shower head and the susceptor by configuring the susceptor in a movable state. See, for example, FIG. 1 disclosed in the Pamphlet of WO 2003/003437. In addition, the substrate processing apparatus has been considered recently configuring the shower head in a movable state rather than the susceptor due to a restriction of the layout around the substrate processing apparatus.
FIG. 11 is a cross-sectional view schematically showing the configuration of the substrate processing apparatus in which the shower head is configured to be movable.
In a substrate processing apparatus 100 of FIG. 11, a shower head 103 disposed to oppose a susceptor 102 in a cylindrical chamber 101 represents a substantial disk shape having an outer diameter that is substantially equal to an inner diameter of chamber 101, and vertically moves like a piston inside chamber 101 by a lift mechanism (not shown). In addition to shower head 103 that moves vertically, a flexible bellows 104 is interposed between shower head 103 and a ceiling wall 101a of chamber 101, and bellows 104 seals the inside of chamber 101 from external air. In addition, in FIG. 11, shower head 103 is represented by a solid line when it descends to the lowest position, and is represented by a dotted line when it ascends to the highest position.